Heat exchanging plate with pressed ridges

ABSTRACT

One side of the heat exchanging plate has a marginal pressed groove for receiving the usual gasket, and both sides have pressed ridges extending side-by-side for crossing and contacting similar ridges on adjacent plates in a plate heat exchanger. The ridges on the same side of the plate as the marginal groove extend all the way to this groove, so that their end surfaces form parts of a side wall of the groove; and the ridges on the opposite side of the plate merge into plate portions between the latter ridges and the groove, these plate portions being situated between the two planes extending through the crests of the ridges on the two sides, respectively, of the plate.

United States Patent 1191 Anderson May 7, 1974 [54] HEAT EXCHANGINGPLATEWITH 3,244,227 4/1966 Usher 165/167 PRESSED RIDGES [75] Inventor:Jarl Anders Andersson, Lund, Primary Exami' wr Manel Amonakas Sweden Assstant ExammerTheoph1l W. Streule, Jr. Attorney, Agent, or FirmCyrus S.Hapgood [73] Assignee: Alta-Laval AB, Tumba, Sweden [22] Filed: Oct. 6,1972 57 S C PP .1 295,428 One side of the heat exchanging plate has amarginal pressed groove for receiving the usual gasket, and [30] ForeignApplication Priority Data both sides have pressedridges extendingside-hy-side O t 8 197 l S d 1273 0 I71 for crosslng and contactingsimilar ridges on ad acent we en plates in a plate heat exchanger. Theridges on the same side of the plate as the marginal groove extend (g1.an the way to this groove so that their end surfaces 58 Field of Search165/166 ME, 167, 186 Parts 1 wan the gmcwe; on the opposite side of theplate merge into plate por- 1 tions between the latter ridges and thegroove, these .[56] References cued plate portions being situatedbetween the two planes UNITED STATES PATENTS extending through thecrests of the ridges on the two 2,814,469 11 1957 Hytte 165/167 sides,respectively, of the plate. 2,181,230 11/1939 Groat 165/167 X y3,661,203 5/1972 Mesher 165/167 2 Claims, 12-Drawing Figures PATENTEUMAY 7 74 SHEET 1 BF 3 The present invention relates to heat exchangingplates of the kind having a pressed marginal groove for a gasketintended to seal between the plate and an adjacent heat exchanging platein a plate heat exchanger, and also having on both sides pressed ridgesextending side-by-side and intended to contact and cross similar ridgeson adjacent plates in the heat exchanger, to serve as spacing meansbetween the plates.

The contact points created between two plates of this kind in a plateheat exchanger must be able to transfer (without substantial deformationof the plate material) forces between the plates caused by clamping themtogether in a plate heat exchanger, and caused by pressure differencesbetween the heat exchanging media treated in the heat exchanger. Thestrength of the plate at these contact points may therefore determinethe thickness of the plate material, the form of the ridgecross-section, and the allowable pressure difference between the heatexchanging media in the plate heat exchanger.

The ridges formed in the plate by a pressing opera tion merge at theirends through sloping end portions into parts of the plate adjacent thesaid gasket groove and which are free from ridges. In plate parts ofthis kind, which are free from ridges and each of which extends acrossseveral ridges on the plate, there is generally no support against theadjacent plates in a plate heat exchanger. Those contact points of aplate which are situated nearest a part like this must thereforetransfer greater forces than contact points located in the middle of afield of pressed ridges. Forces which really should be transferred bythe plate part free from ridges must thus be transferred through saidnearest contact points instead.

It is especially important that the ridges shall not be deformed atthese contact points nearest the gasket groove, for the height of theridges in these areas determines the thickness to which the gasket willbe compressed. I

Since the plate must be dimensioned and formed with regard to thegreatest forces that may arise, the plate will have an optimumdirnensiononly in the areas of the few contact points situated nearestthe plateportions which are free from ridges, while the rest of the plate (i.e.,the main part of the plate) will be overdimensioned.

An object of the present invention is to provide a plate over whichthere is a more even distribution of the forces to be transferredthrough all of the contact points, so that the main part of the platemay have at least substantially an optimum dimension.

This object is fulfilled according to the invention by a plate on whichthe ridges situated on the same side of the plate as the gasket grooveextend all the way to the gasket groove (i.e., their end surfaces formparts of the side wall of the gasket groove), while the ridges on theopposite side of the plate merge into plate portions located between theridges and the gasket groove and which are .situated between the planesextending through the crests of the ridges on both-sides of the plate.With aconstruction of this kind it is possible, without changing theinclination of the end portionsof the ridges, to obtain contact pointssubstantially closer to the plate portions which are free from ridgesthan was previously possible. In this way the force to be transferredthrough these contact points can be reduced, and the main part of theplate need not be overdimensioned as much as heretofore.

The invention will be described in more detail below with reference tothe accompanying drawings.

In the drawings,

FIGS. 1 and la are face views of two plates of the kind involved here;

FIG. 2 is a fragmentary sectional view of two such plates as paired toform points of contact between them in a plate heat exchanger;

FIG. 3 is a face view of a further plate of the kind involved here; I

FIGS. 4a and 4b are plan and cross-sectional views, respectively, ofpart of a previously known plate;

FIG. 5a is a plan view of part of a plate incorporating various forms ofthe invention; and

FIGS. 5b, 6, 7, 8 and 9 are cross-sectional views on the lines -VII-Vll,VIII-VIII, IX-IX, X-X and Xl-XI, respectively, in FIG. 5a.

. The two plates 1 and 2 as shown in FIGS/1 and la are identical (notnecessary), and one of them is turned 180 relative to the other in theplane of the drawing. Each plate has ridges formed on both sides by apressing operation. The ridges visible in FIGS. 1 and la are designated3. The ridges situated on the other side of each plate are formed by theback sides of the troughs located between the ridges 3 and which aredesignated 4. The two plates have openings 58 serving as inlets andoutlets for two heat exchanging media flowing to and from respectiveplate interspaces which are formed when several plates are assembled ina conventional manner in a plate heat exchanger.

In FIG. 2 there are shown fragments of the plates 1 and 2 placedrelative to each other as in a plate heat exchanger. As can be seen,contact points 9 are created between the plates, where the ridges of theplatescross and contact each other.

Normally, plates of the kind shown in FIGS. 1 and la are not entirelycovered by ridges formed by pressing.

In FIG. 3 there is shown with broken lines a narrow portionl0 of aplate. This narrow portion 10, extending along the long sides oftheplate and close to the inlet and outlet openings 5-8, is free fromridges for the reason that the plate in this area'has a groove for asocalled marginal gasket-The. latter (not shown) is intended to closefrom the surrounding atmosphere the interspace formed between the twoplates when they abut each other in a plate heat exchanger. The areasurrounded by the narrow portion 10 is provided with the ridges (notshown).

A groove 22 is pressed near the edge of the previously known plate shownin FIGS. 4a and 4b, this groove serving to receive a marginal gasket(not shown). A plane portion of the plate, situated between the groove22 and the ridges 3 and 4 pressed in the heat transferring portion ofthe plate, is designated 10. As can be seen from the drawing (FIG. 4b),the crests of the ridges 3 are situated in the same plane as the saidportion 10, and the ridges 3 therefore may be said to extend all the wayto the groove '22. The ridges 4 on the other side of the plate extendonly to the portion 10, however, and the ridges 4 therefore willdetermine how near the gasket groove 22' it is possible to obtaincontact points between two plates in a plate heat exchanger. Thesmallest distance between the bottom of the gasket groove 22 and acontact point of this kind is marked C in FIG. 4b. The greater thisdistance is, the greater the unsupportedplate portion will be, and thegreater the force to be transferred at the contact point.

The plan view of FIG. 5a shows five different embodiments I-V of theregion of the gasket groove in a plate according to the invention. Theridges on the upper face of the plate are designated 18, while theridges on the lower face are designated 19, the latter ridges beingformed by the valleys between the upper ridges 18. The gasket groove isdesignated 23.

When comparing FIG. 4a and FIG. 5a, it will be noted that the distancein the plate of FIG. 5a between the ends .of the ridges.l9 and thegasket groove 23 (in all embodiments I-V) is smaller than the distancebetween the ends of the ridges 4 and the groove 22 in the prior artplate of FIG. 4a. This is a result of the fact that the portion 10 inthe area between the ends of the ridges 4 and the gasket groove 22(FIGS. 4a and 4b) has been displaced to a level half waybetween the twoplanes extending through the crests of the ridges 18 and 19,respectively, on opposite sides of the plate. In the embodiment V, thewidth of this portion (designated 24 in FIG. 5a) has been kept as largeas the width of the corresponding portion 10 in FIG. 4a while in theother embodiments I-IV the width of the same portion 24 has been reducedto a minimum. In FIG. 5b there is shown a cross-section of theembodiment V along the line VII- VII in FIG. 5a, while in FIG. 6 thereis shown the corresponding cross-section along the lines VIII-VIII inFIG. 5a, which is common to the other embodiments l-IV. In FIG. 5b, thesmallest distance obtainable between the bottom of the gasket groove 23and the nearest contact point between two plates in a plate heatexchanger is marked D. As can be seen, this distance D is smaller thanthe corresponding distance C in the prior art plate of FIGS. 4a and 4b.A broken line 25 in FIG. 5b shows where the ridges 4 of the prior artplate end at the region of the gasket groove. Consequently,

the contact points nearest the gasket groove 23 in the plate accordingto the invention do not need to transfer such great forces as thecontact points nearest the gasket groove 22 in the prior art plate.

In FIG. 5a, the embodiments II, III and IV are shown with grid-likeareas 26, 27 and 28, respectively. These areas are other portions of theplate which, like theportion 24, are situated at a lever half waybetween the planes extending through the crests of the ridges l8 and 19situated on opposite sides of the plate. In the embodiments II and III,these areas 26 and 27, respectivley, are directly connected in the sameplane with the portions 24, while in the embodiment IV there is a smallinterspace between the area 28 and the portion 24.

I claim:

1. A heat exchanging plate having a peripheral part provided with apressed groove for receiving a gasket adapted to seal between the plateand an adjacent heat exchanging plate in a plate heat exchanger, saidgroove having opposing side walls which are substantially continuous,the plate also having on each side thereof pressed ridges extending inside-by-side relation for crossing and contacting similar ridges onadjacent plates in said heat exchanger to form spacing means between theplates, the plate being characterized in that the ridges located on thesame side of the plate as the gasket-receiving groove extend all the wayto said groove, whereby the end surfaces of said sameside ridges formparts of said side wall of said groove, the ridges on the opposite sideof the plate merging into plate portions between said opposite-sideridges and said groove, said plate portions being situated between thetwo planes extending through the crests of said same-side and saidopposite-side ridges, respectively.

2. A heat exchanging plate according to claim 1, in which said plateportions are situated half way between said two planes.

1. A heat exchanging plate having a peripheral part provided with apressed groove for receiving a gasket adapted to seal between the plateand an adjacent heat exchanging plate in a plate heat exchanger, saidgroove having opposing side walls which are substantially continuous,the plate also having on each side thereof pressed ridges extending inside-by-side relation for crossing and contacting similar ridges onadjacent plates in said heat exchanger to form spacing means between theplates, the plate being characterized in that the ridges located on thesame side of the plate as the gasket-receiving groove extend all the wayto said groove, whereby the end surfaces of said sameside ridges formparts of said side wall of said groove, the ridges on the opposite sideof the plate merging into plate portions between said opposite-sideridges and said groove, said plate portions being situated between thetwo planes extending through the crests of said same-side and saidopposite-side ridges, respectiVely.
 2. A heat exchanging plate accordingto claim 1, in which said plate portions are situated half way betweensaid two planes.